Compressor diffuser having vanes with variable cross-sections

Abstract

A diffuser is disclosed for use with a compressor. The compressor diffuser may have a ring-shaped generally flat plate, a plurality of first vanes disposed radially around an upper surface of the plate, and a plurality of second vanes shorter than the first vanes. Each of the second vanes may be connected to the plate between adjacent first vanes. The first and second vanes may each have a high-pressure side and an opposing low-pressure side, and each may tilt towards one of its corresponding high- and low-pressure sides at a lean angle that changes along its meridional length.

What is claimed is: 
     
         1 . A compressor diffuser, comprising:
 a ring-shaped generally flat plate;   a plurality of first vanes disposed radially around an upper surface of the plate; and   a plurality of second vanes shorter than the first vanes, each of the second vanes being connected to the plate between adjacent first vanes,   wherein:
 each of the first and second vanes includes a high-pressure side and an opposing low-pressure side; and 
 each of the first and second vanes tilts towards one of its corresponding high- and low-pressure sides at a lean angle that changes along its meridional length. 
   
     
     
         2 . The compressor diffuser of  claim 1 , wherein each of the first and second vanes have a vane angle that also changes along its meridional length, with an absolute value a range of about 36-76 degrees. 
     
     
         3 . The compressor diffuser of  claim 2 , wherein the vane angle is greatest for the first vanes at about 15-20% of a meridional length from a leading edge to a trailing edge. 
     
     
         4 . The compressor diffuser of  claim 3 , wherein the vane angle is lowest for the first vanes at the trailing edge. 
     
     
         5 . The compressor diffuser of  claim 2 , wherein the vane angles associated with the first and second vanes relative to a percent of meridional length of the first vanes are about the same. 
     
     
         6 . The compressor diffuser of  claim 2 , wherein the vane angles associated with the first and second vanes also vary along a height of the first and second vanes between a hub face and a shroud face. 
     
     
         7 . The compressor diffuser of  claim 6 , wherein the vane angles are greatest at one of the hub face or shroud face. 
     
     
         8 . The compressor diffuser of  claim 1 , wherein leading edges of the second vanes are located radially outward of leading edges of the first vanes. 
     
     
         9 . The compressor diffuser of  claim 8 , wherein the leading edges of the second vanes are located at a radial position corresponding to about 25-55% of a meridional length of the first vanes. 
     
     
         10 . The compressor diffuser of  claim 9 , wherein trailing edges of the second vanes are located at about the same radial location as trailing edges of the first vanes. 
     
     
         11 . The compressor diffuser of  claim 1 , wherein at least one of the second vanes is located asymmetrically between adjacent first vanes. 
     
     
         12 . The compressor diffuser of  claim 11 , wherein each of the second vanes is located within about 5% of a line of symmetry located between adjacent first vanes. 
     
     
         13 . The compressor diffuser of  claim 1 , wherein a density of the first and second vanes varies relative to an annular position around the plate. 
     
     
         14 . The compressor diffuser of  claim 13 , wherein a greater density of the first and second vanes is located at a region of the plate corresponding with a tongue of a shroud scroll. 
     
     
         15 . The compressor diffuser of  claim 1 , wherein each of the first and second vanes includes a generally tapered trailing edge and a generally rounded leading edge. 
     
     
         16 . The compressor diffuser of  claim 15 , wherein a thickness of each of the first and second vanes varies along a meridional length of the first and second vanes. 
     
     
         17 . The compressor diffuser of  claim 16 , wherein the thickness of each of the first vanes relative to a percent of the meridional length of the first vanes is about the same as the thickness of each of the second vanes relative to a percent of the meridional length of the first vanes. 
     
     
         18 . The compressor diffuser of  claim 17 , wherein the thickness is greatest at about 25-40% of the meridional length for each of the first vanes. 
     
     
         19 . The compressor diffuser of  claim 1 , wherein:
 each of the first vanes includes a hub face and a shroud face; and   a solidity ratio of each of the first and second vanes ranges from about 0.7 to 1.4 between the hub face and the shroud face.   
     
     
         20 . The compressor diffuser of  claim 1 , wherein the first vanes include a leading edge elliptical ratio of about 2-6:1. 
     
     
         21 . The compressor diffuser of  claim 20 , wherein the second vanes include a leading edge elliptical ratio of about 4-10:1. 
     
     
         22 . The compressor diffuser of  claim 21 , wherein the leading edge elliptical ratio of at least one of the first vanes and the second vanes increases according to height from a hub face to a shroud face. 
     
     
         23 . The compressor diffuser of  claim 21 , wherein a trailing edge elliptical ratio of the first and second vanes is about 2-4:1. 
     
     
         24 . A compressor diffuser, comprising:
 a ring-shaped generally flat plate;   a plurality of first vanes disposed radially around an upper surface of the plate; and   a plurality of second vanes shorter than the first vanes, each of the second vanes being connected to the plate between adjacent first vanes,   wherein a density of the first and second vanes varies relative to an annular position around the plate.   
     
     
         25 . The compressor diffuser of  claim 24 , wherein a greater density of the first and second vanes is located at a region of the plate corresponding with a tongue of a shroud scroll. 
     
     
         26 . The compressor diffuser of  claim 24 , wherein:
 leading edges of the second vanes are located radially outward of leading edges of the first vanes; and   trailing edges of the second vanes are located at about the same radial location as trailing edges of the first vanes.   
     
     
         27 . The compressor diffuser of  claim 26 , wherein leading edges of the second vanes are located at a radial position corresponding to about 25-55% of a meridional length of the first vanes. 
     
     
         28 . The compressor diffuser of  claim 24 , wherein at least one of the second vanes is located asymmetrically relative to adjacent first vanes. 
     
     
         29 . The compressor diffuser of  claim 28 , wherein each of the second vanes is located within about 5% of a line of symmetry located between adjacent first vanes. 
     
     
         30 . The compressor diffuser of  claim 24 , wherein:
 each of the first and second vanes includes a generally tapered trailing edge and a generally rounded leading edge; and   a thickness of each of the first and second vanes varies along a meridional length.   
     
     
         31 . The compressor diffuser of  claim 30 , wherein a thickness of each of the first vanes relative to a percent of the meridional length of the first vanes is about the same as a thickness of each of the second vanes relative to a percent of the meridional length of the first vanes. 
     
     
         32 . The compressor diffuser of  claim 31 , wherein the thickness is greatest at about 25-40% of the meridional length for each of the first and second vanes. 
     
     
         33 . The compressor diffuser of  claim 24 , wherein:
 each of the first vanes includes a hub face and a shroud face; and   a solidity ratio of each of the first and second vanes ranges from about 0.7 to 1.4 along a height from the hub face to the shroud face.   
     
     
         34 . The compressor diffuser of  claim 24 , wherein:
 the first vanes include a leading edge elliptical ratio of about 2-6:1;   the second vanes include a leading edge elliptical ratio of about 4-10:1; and   the first and second vanes include a trailing edge elliptical ratio of about 2-4:1.   
     
     
         35 . The compressor diffuser of  claim 34 , wherein the leading and trailing edge elliptical ratios of the first and second vanes increases according to height from a hub face to a shroud face. 
     
     
         36 . A turbocharger, comprising:
 a housing at least partially defining a compressor shroud with a scroll inlet and a turbine shroud with a scroll outlet;   a turbine wheel disposed within the turbine shroud;   a compressor wheel disposed within the compressor shroud;   a shaft connecting the turbine wheel to the compressor wheel;   a ring-shaped generally flat plate located at a periphery of the compressor wheel;   a plurality of first vanes disposed radially around an upper surface of the plate; and   a plurality of second vanes shorter than the first vanes, each of the second vanes being connected to the plate between adjacent first vanes,   wherein:
 the first and second vanes each includes a high-pressure side and an opposing low-pressure side; 
 each of the first and second vanes tilts towards one of the high- and low-pressure sides at a lean angle that changes along its length; 
 each of the first and second vanes has a vane angle that varies along its meridional length and height within a range of absolute values of about 36-76 degrees; and 
 a greater density of the first and second vanes is located at a region of the plate corresponding with a tongue of the scroll inlet of the compressor shroud.